On Wed, Oct 10, 2018 at 07:22:48PM +0200, Lubomir Rintel wrote: > The OLPC XO-1.75 Embedded Controller is a SPI master that uses extra > signals for handshaking. It needs to know when is the slave (Linux) > side's TX FIFO ready for transfer (the ready-gpio signal on the SPI > controller node) and when does it wish to respond with a command (the > cmd-gpio property). > > Signed-off-by: Lubomir Rintel <lkundrak@xxxxx> > --- > .../bindings/misc/olpc,xo1.75-ec.txt | 24 +++++++++++++++++++ > 1 file changed, 24 insertions(+) > create mode 100644 Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt > > diff --git a/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt b/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt > new file mode 100644 > index 000000000000..14385fee65d2 > --- /dev/null > +++ b/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt > @@ -0,0 +1,24 @@ > +OLPC XO-1.75 Embedded Controller > + > +Required properties: > +- compatible: Should be "olpc,xo1.75-ec". > +- cmd-gpio: gpio specifier of the CMD pin cmd-gpios > + > +The embedded controller requires the SPI controller driver to signal readiness > +to receive a transfer (that is, when TX FIFO contains the response data) by > +strobing the ACK pin with the ready signal. See the "ready-gpio" property of the This will need updating based on the SPI binding. > +SSP binding as documented in: > +<Documentation/devicetree/bindings/spi/spi-pxa2xx.txt>. > + > +Example: > + &ssp3 { > + spi-slave; > + status = "okay"; Don't show status in examples. > + ready-gpio = <&gpio 125 GPIO_ACTIVE_HIGH>; > + > + slave { > + compatible = "olpc,xo1.75-ec"; > + spi-cpha; > + cmd-gpio = <&gpio 155 GPIO_ACTIVE_HIGH>; > + }; > + }; > -- > 2.19.0 >